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At least 289 records · Page 16Linked to original sources
PubMed1977

Resistant levels of houseflies to six kinds of synthetic insecticides in the Philippines.

The resistant levels of houseflies to six kinds of insecticides: DDT, Pyrethrins, malathion, Sumithion, Baytex and DDVP, were examined on 15 strains collected in the Philippines. It was found that most housefly colonies in the Philippines showed higher susceptibility to those insecticides than the Takatsuki strains, especially to DDT. The range of LD50 values to malathion were between 1.775 microgram and 0.0975 microgram per fly. Among 15 strains collected in the Philippines, 7 showed higher LD50 values to malathion than the Takatsuki strain. These values mean that the houseflies in the Philippines are increasing their resistance to malathion.

Animals↗
PubMedDate not supplied

The effects of selected fungicides and insecticides on growth and thebaine production of Papaver bracteatum.

The fungicides benlate, maneb, and captan depressed plant growth, thebaine concentration, and thebaine yield per plant when administered chronically to Papaver bracteatum. The chronic administration of dicofol inhibited plant growth and thebaine yield per plant, but did not affect thebaine concentration. Malathion and pyrethrins had no adverse effects on either plant growth or thebaine content.

Fungicides, Industrial↗
PubMed1998

Lack of clinical symptoms in an acute arsenic poisoning: an unusual case.

A 32-y-old woman was admitted to Granada University Hospital for attempted suicide by ingestion of an ant-killer containing 10% sodium arsenate and 5% pyrethrins. Neither gastrointestinal distress nor hepatic, renal, or neurologic disturbances were clinically observed. However, the presence of toxic levels of arsenic (14 mg/L) was confirmed by atomic absorption spectrophotometry in a sample of urine taken about 12 h after poisoning. An uneventful clinical course was observed, and the patient was discharged after 6 days upon her request. Long-term follow-up was unavailable. From a Medline search over the years 1985-1998 only one similar report also dealing with sodium arsenate was found. Different pathogenic hypotheses are discussed in the light of the clinical data.

Adult↗
PubMed2000

Interventions for treating scabies.

BACKGROUND: Scabies is a common public health problem with an estimated prevalence of 300 million. Infestation can cause considerable discomfort and intense itching. Severe adverse effects have been reported for some drugs used to treat scabies. OBJECTIVES: The objective of this review is to assess the effects and toxicity of topical and systemic drug treatment for scabies. SEARCH STRATEGY: We searched the Cochrane Infectious Diseases Group trials register, the Cochrane Controlled Trials Register, Medline, Embase, military records, traditional medicine databases. We also contacted international specialist centres and drug manufacturers. SELECTION CRITERIA: Randomised controlled trials of any drug treatment for scabies. Tolerability and toxicity were sought in any study of humans taking any drug treatments for scabies. DATA COLLECTION AND ANALYSIS: Two reviewers assessed trial quality and extracted data. MAIN RESULTS: Eleven trials were included (7 compared drug treatments, 2 compared treatment regimes, 1 compared the drug vehicle and 1 was a community intervention). Compared with placebo in one small trial, ivermectin was associated with a significant higher clinical cure rate at seven days. Permethrin appeared to be more effective than crotamiton for clinical and parasitic cure rates. Permethrin appeared to be better than gamma benzene hexachloride for clinical cure rates in two small trials but had no advantage in the largest trial (test for heterogeneity p< 0.001). Permethrin also appeared more effective in reducing itch persistance than gamma benzene hexachloride. There appeared to be no difference in clinical cure rates between crotamiton and gamma benzene hexachloride. Single trials assessed: the effectiveness of oral versus topical treatment (ivermectin versus benzyl benzoate); treatment vehicle (pork fat versus cold cream); and mass community treatment (ivermectin) but were too small to demonstrate an effect. No randomised trials of malathion were identified. Serious adverse drug reactions (including death and convulsions) have been reported in other studies of scabies drugs, most notably gamma benzene hexachoride and ivermectin. REVIEWER'S CONCLUSIONS: The evidence that permethrin is more effective than gamma benzene hexachloride is inconsistent. Permethrin appears to have less potential serious drugs reactions than gamma benzene hexachloride although this is not derived from trial data. More research is needed of the safety and effectiveness of ivermectin and malathion compared to permethrin, on community management, and on different regimes and vehicles for topical treatment.

Hexachlorocyclohexane↗
PubMed1986

1% permethrin cream rinse vs 1% lindane shampoo in treating pediculosis capitis.

The therapeutic efficacy and tolerance of a single application of 1% permethrin cream rinse, applied for ten minutes, and a single application of 1% lindane shampoo applied, as recommended by the manufacturer, for four minutes, against the head louse Pediculus humanus var capitis were compared in a single-blinded, randomized, controlled clinical trial. Of 573 patients enrolled at eight centers, 559 were assessable for tolerance and 508 for efficacy. Of the 257 patients treated with 1% permethrin cream rinse, 99% were lice free at 14 days; of the 251 patients treated with 1% lindane shampoo, 85% were lice free at 14 days. The difference is statistically significant. For both treatments, adverse experiences were infrequent, mild, and usually difficult to distinguish from the symptoms of head lice infestation. A single ten-minute application of 1% permethrin cream rinse was well tolerated, highly effective, and therapeutically superior to a single four-minute application of 1% lindane shampoo.

Clinical Trials as Topic↗
PubMed1999

Exact simultaneous confidence bands for a collection of univariate polynomials in regression analysis.

We discuss a simple simulation method for construction of exact confidence bands, having a pre-assigned confidence level simultaneously for several regression functions which are univariate polynomials in the predictors. This is accomplished by combining and extending existing results in a manner that permits both finite and infinite ranges for individual predictor variables. We illustrate the method for a logistic regression model with both dichotomous and continuous predictors.

Animals↗
PubMedDate not supplied

Metabolism and bioaccumulation of fenvalerate and its metabolites in rat organs.

Metabolism and bioaccumulation of fenvalerate and its fenvalerate its metabolites in liver, kidney and brain of rat following the oral administration of a sub-lethal dose (15 mg/kg) of the pesticide for 7, 15 and 30 day periods was investigated by high-performance liquid chromatography (HPLC) in terms of the relative mole concentrations in rat tissues. The cleavage of the ester linkage in fenvalerate yielding two metabolites was found to be primary step in the biodegradation of fenvalerate in rat organs. These metabolites were purified to homogeneity by HPLC and characterized by infra-red spectroscopy as 4-chloro-alpha-(1-methylethyl) benzeneacetic acid and 3-phenoxy benzoic acid.

Animals↗
PubMedDate not supplied

Insecticide-induced changes in secretory activity of the thyroid gland in rats.

The present study was conducted to examine the effect of organochlorine (Heptachlor, Benzene hexachloride (BHC)), organophosphorus (Malathion, Monitor) and pyrethroid (Karate, Talstar) insecticides on the thyroid secretory function in rats. Heptachlor (0.5 mg per rat), BHC (0.66 mg per rat) Malathion (0.06 mg per rat), Monitor (0.2 mg per rat), Karate (0.2 mg per rat), Talstar (0.5 mg per rat) were orally administered to young adult rats for 21 days. Serum concentrations of triiodothyronine (T3), thyroxine (T4) and thyrotrophin (TSH) were determined by using specific radioimmunoassays. Body weight was not affected by treatment with any insecticide except Talstar (P < 0.01). Among organochlorine and organophosphorus insecticides, treatment with BHC and Malathion, respectively, led to a significant decrease (P < 0.01) in serum concentration of T3 and T4. Administration of BHC and Malathion also increased (P < 0.01) TSH secretion. Treatment with both of the pyrethroid insecticides similarly induced significant suppression (P < 0.01) of serum T3 and T4 levels, and concomitant stimulation (P < 0.01) of TSH concentrations. The T4/T3 ratio was decreased (P < 0.05) in rats treated with Karate but not with any other insecticide. These data indicate that immense care is warranted in the use of insecticides, because they not only affect the liver, kidney and other organs but also may alter the activity of the endocrine glands.

Animals↗
PubMedDate not supplied

Effect of chlorfenvinphos, cypermethrin and their mixture on the intestinal transport of leucine and methionine.

We assessed the effect of 2-week oral treatment with chlorfenvinphos, cypermethrin and their mixture in a dose of 5% LD50 on the intestinal transport of L-leucine (Leu) and L-methionine (Met) in male Wistar rats. Both in vitro (jejunal slices) and in vivo (intestinal perfusion) methods were employed in the study, using Leu and Met labelled with 14C as markers of the investigated processes. Additionally, in the in vitro study, concentrations of two amino acids were measured in the whole blood, serum, liver and perfused segment of the intestine. In the in vitro study the kinetic constants describing the active and passive Leu and Met uptake were determined. The active uptake was found to be particularly affected by oral intoxication with chlorfenvinphos, cypermethrin and their mixture. This susceptibility was seen as major alterations in the parameters of active uptake, i.e. Jm and Ki constants in the pesticide-exposed groups as compared to controls. In the in vivo study we found a decreased rate of Leu and Met disappearance from the intestinal lumen, decreased blood concentrations of Leu and Met and decreased liver content of Leu in the pesticide-exposed groups as compared to controls. The findings allow the conclusion that oral administration of chlorfenvinphos, cypermethrin and their mixture in a dose of 5% LD50 impairs the intestinal transport of Leu and Met and alters their distribution in the rodent body.

Animals↗
PubMedDate not supplied

Dual role of testosterone in fenvalerate-treated mice with respect to thyroid function and lipid peroxidation.

Effects of testosterone propionate (TP, 2.5 mg kg(-1) body weight) in fenvalerate-induced (120 mg kg(-1) body weight) thyroid dysfunction and lipid peroxidation were investigated in male mice. Testosterone propionate aggravated in the inhibition of hepatic type I iodothyronine 5'-monodeiodinase (5'D-I) activity, coupled with a decrease in serum triiodothyronine (T3) concentration in pesticide-treated mice. However, it could ameliorate the toxicity as indicated by decreased hepatic lipid peroxidation (LPO) with a marginal but significant increase in superoxide dismutase and catalase activities following fenvalerate treatment. While protective effects of testosterone on LPO indicated its antiperoxidative property, the decrease in 5'D-I activity could be because of the increased accumulation of fenvalerate in the tissues following TP administration.

Animals↗
PubMedDate not supplied

Pyrethroid decrease in central nervous system from nerve agent pretreatment.

We studied the effect of pyridostigmine bromide, a nerve agent prophylactic, on the central nervous system (CNS) uptake of [14C]permethrin, a pyrethroid insecticide, at scaled human-equivalent exposures in rats using accelerator mass spectrometry (AMS). AMS detects 14C at attomole sensitivities and determines the tissue distribution of 14C-labeled compounds. Pyridostigmine bromide in chow at 7.75 mg kg(-1) per day lowered the CNS tissue levels of permethrin, dosed at 4.75 microg kg(-1), in the CNS of rats by 30%. These results are inconsistent with hypothesized synergy of such compounds as a precursor to 'Gulf War syndrome'.

Animals↗
PubMedDate not supplied

Micronuclei formation in bone marrow cells of rats treated with meothrin (synthetic pyrethroid).

The production of micronuclei in rat bone marrow cells by the synthetic pyrethroid insecticide meothrin was investigated. Three different doses of meothrin were orally administered to rats for 14 consecutive days. All tested doses of meothrin increased the frequency of micronucleated polychromatic erythrocytes but the increase was statistically significant only at the two highest doses. Meothrin also affected the rate of bone marrow cell proliferation, as determined by changes in the ratio of polychromatic erythrocytes to normochromatic erythrocytes.

Administration, Oral↗
PubMedDate not supplied

Is triiodothyronine capable of ameliorating pyrethroid-induced thyroid dysfunction and lipid peroxidation?

A study on the effect of triiodothyronine (T3) in the regulation of pyrethroid (fenvalerate)-induced thyroid dysfunction and lipid peroxidation was carried out in male mice. Fenvalerate (120 mg kg(-1) body wt. daily for 15 days) administration led to a decrease in the serum concentration of thyroid hormones and the activity of hepatic type I iodothyronine 5'-monodeiodinase (5'D-I) and an increase in the level of lipid peroxidation. The decrease in the activity of hepatic 5'D-I due to the administration of fenvalerate was restored with the administration of T3 (7 microg kg[-1] body wt. on alternate days). The increased level of lipid peroxidation was also ameliorated by T3. However, T3 could not restore the serum concentration of thyroxine (T4), only that of T3. We suggest that the ameliorating role of T3 in the fenvalerate-intoxicated mice could be the result of the lipogenic action of the thyroid hormone, which in turn led to the restoration of 5'D-I activity.

Animals↗